“EXPERIMENTAL ANALYSIS OF POST STRENGTHENING MASONRY VAULTS BY W-WRAP TECHNIQUE

The paper deals about the effects of the confinement due to the -Wrap technology proposed by the authors and consists in applying the CFRP layer to assume a  shape around a concrete core realized at the vault extrados as a supporting rib. The study reports the results obtained by the experimental investigation carried out on vault specimens scaled to 1:2 size undergoing a monotonic load applied to one fourth of the span. This load condition in fact is the most severe and it can be considered as the one that better represents the seismic load. The data were compared to the ones obtained by the traditional technique based on the use of CFRP directly bonded to the structural masonry element. The -Wrap system permits us to obtain a very relevant result, which leads to a relevant increase of the bearing capacity of the vaults as well as a great ability of energy dissipation. This is due to the great resistance and ductility of the concrete ribbing, confined by the composite, with a lower CFRP material quantity in respect to the traditional system. Besides, the strengthening system allows the transfer of the horizontal load from the vault to the masonry bays and at the same time, it is capable, in the case of any subsiding of the abutments of vaults or vertical accelerations, of avoiding the failure of parts of the vault since they remain attached to the ribbings.